There is known an infrared sensor including a film-like infrared absorbing portion formed on a semiconductor substrate such as a silicon substrate, a sensing element formed on the infrared absorbing portion, and a switching element for reading out an output of the sensing element (see PTL 1). The infrared absorbing portion has a multilayer structure, in which material, thickness, and the like, are determined such that remaining stress is reduced so as to reduce breakage and operation abnormality of the switching element is reduced. Other techniques are disclosed in, for example, PTLs 2 and 3.